1. Field of the Invention
The present invention relates to rubber shaped articles comprising a rubber shaped product made of EPDM and a finishing layer of gelatinized PVC formed thereon, and a process for producing the same.
The rubber shaped articles having a finishing layer of the present invention can be used as internal and external automotive trims such as glass weather strip (FIG. 2), side mole (FIG. 3), glass outer, glass inner, glass run and window frame rubber in addition to such weather strips as shown in FIGS. 1, 2, 6, 8, 9, 12 and 13.
2. Background Information
Many of the main bodies of weather strips used in automobiles and the like are usually made of EPDM from the viewpoint of weather resistance, ozone resistance, heat resistance, etc.
Because of the recent growing demand for improvement in the decorative design of automobiles, it is desirable in some cases that the surface to be decorated with a weather strip is finished to become the same cloth-like or leather-like surface as that of the internal trim. In this case, there is a method comprising attaching cloth or leather to the surface to be decorated (see Japanese Utility Model Registration Unexamined Publication No. 62-88655).
In addition, owing to the recent growing demand for improvement in the decorative design of automobiles, there is an eager desire for the advent of a weather strip with a decorative surface having a bright and subdued, black or chromatic color.
PVC paste for solidification cannot impart softness with respect to touch and appearance and cannot sufficiently satisfy the demand for goods of higher grade.
However, it has been substantially impossible to obtain a bright and subdue, black or chromatic color on the surface of a rubber shaped article without a treatment after shaping because of characteristics of the rubber material itself.
In addition, it has been difficult to form a layer of PVC paste gelatinized by heating, directly on a rubber substrate made of EPDM, with satisfactory adhesion. Therefore, the formation of said layer requires pretreatments such as buffing and primer treatment of a vulcanized rubber surface. These pretreatments require a large number of steps.
Furthermore, for finishing the surface to be decorated of a rubber substrate (a weather strip) to make the same, for example, cloth-like, the surface to be decorated of the rubber substrate after vulcanization should be subjected to a large number of steps such as buffing, defatting, primer coating, coating with an adhesive, attachment of cloth, curing of the adhesive, etc. Therefore, the productivity is not satisfactory.
A list of the abbreviations of polymers, plastisizers and the like used in the present specification is shown below.
NBR--.alpha.,.beta.-unsaturated nitrile-conjugated diene copolymer rubber a typical example of which is nitrile rubber.
EPDM--ethylene-.alpha.-olefin-non-conjugated diene copolymer rubber a typical example of which is ethylene-propylene-diene ternary rubber.
SBR--aromatic vinyl compound-conjugated diene copolymer rubber a typical example of which is styrene-butadiene rubber.
PVC--polyvinyl chloride.
DOP--dioctyl phthalate.